'Relevant area' shown in data download page different to extent

[DataOfficer]

We are sharing some datasets privately to community users in ArcGIS Hub Premium, to allow them to download their own data submissions. The extent of the hosted feature layer, the hosted feature layer view, the ArcGIS Hub basemap and our organisation is set to the United Kingdom. However, when viewing the data before download in ArcGIS Hub, the extent is much larger. Why is this and how can I change it to our preferred extent?

Here is an example of what our users see when accessing the dataset via ArcGIS Hub (note the blue dot showing their data): 

[Anonymous User]

Thanks for reaching out! As you note, there are a number of places where extents can be set, so it can be difficult to debug. I'm not exactly sure where the global extent is coming from, but you should be able to manually override by setting the item extent in ArcGIS Online. If you continue to notice odd extents with your items after doing so, please let us know.

[DataOfficer]

Hi Patrick,
As far as I am aware I have set the correct extent in all possible locations. That includes setting the extent in ArcGIS Online as you can see here: